WO2014090786A1

WO2014090786A1 - Tool holder

Info

Publication number: WO2014090786A1
Application number: PCT/EP2013/076052
Authority: WO
Inventors: Aaron Wiedner; Thomas Bader; Thomas Hofbrucker
Original assignee: Hilti Aktiengesellschaft
Priority date: 2012-12-13
Filing date: 2013-12-10
Publication date: 2014-06-19
Also published as: DE102012223099A1; EP2931479A1; EP2931479B1

Abstract

The tool holder (8) for a hand-held machine tool (1), in particular a hammer drill (1), has a tube (19; 87), the inner surface (52, 53; 86) of which defines a receiving space (26; 85), which is coaxial with respect to a working axis (5), for a plug-in end (7) of a tool (4). The outer surface (24, 25) of the tube (19) is equipped with a groove (69) which encircles the axis (5). A radially movable locking element (30) protrudes partially into the receiving space (26; 85) through a radial opening in the tube (87). A locking sleeve (31, 32) is guided on the outer surface (24, 25) of the tube (19; 87) so as to be movable along the axis (5). In a normal position, the locking sleeve bears against the locking element (30) in a radial direction. A spring (36) drives the locking sleeve (31, 32) into the normal position. The locking sleeve (31, 32) is supported, counter to the force of the spring (36), on a securing bracket (68). The securing bracket (68) is inserted into the groove (69). The securing bracket (68) encircles the groove (69) over less than 250 degrees, preferably over more than 180 degrees.

Description

toolholder

FIELD OF THE INVENTION

The present invention relates to a tool holder for a hand-held rotary hammer or other rotary machine tools.

DISCLOSURE OF THE INVENTION

The tool holder according to the invention for a hand tool, in particular a hammer drill has a tube whose inner surface defines a coaxial to a working axis receiving space for a male end of a tool. The outer surface of the tube is provided with a circumferential groove around the axis. A radially movable locking member projects through a radial opening in the tube partially into the receiving space. A locking sleeve is movably guided on the outer surface of the tube along the axis. The locking sleeve is in a basic position on the locking element in the radial direction. A spring drives the locking sleeve into the basic position. On a securing bracket, the locking sleeve is supported against the force of the spring. The circlip is inserted in the groove. The securing bracket encloses the groove by less than 250 degrees, preferably by more than 180 degrees. One embodiment provides that the securing bracket encloses the groove between 200 degrees and 240 degrees. The safety bracket advantageously engages only slightly the tube. A user can secure the safety bar with easily accessible tools, e.g. pliers or a screwdriver. Removing the safety bar, the user can strip the other components of the tool holder from the pipe and replace it if necessary.

The inner contour of the securing bow can lie flush against the groove bottom, that is, for example, be part-cylindrical. The enclosing angle defines the opening width of the clamp in relation to the diameter of the circumferential groove. The opening width is smaller than the diameter for a clamping action. The circlip is placed perpendicular to the tube and removed. A snap ring is slid along the axis onto the pipe. An embodiment provides that the outer surface has a flat key surface adjoining the groove along the axis and the securing bow has an anti-rotation lock for an orientation of the securing bow defined for the key surface. The circlip has two opposed clamping legs which rest in the groove and a pin between the clamping legs to the axis projecting. The mandrel engages in a circumferentially limited recess. The given orientation can facilitate assembly and disassembly.

An embodiment provides that the locking sleeve has a projecting in the direction of the securing bracket hollow cylindrical projection. The radial inner surface of the projection abuts against the securing bracket when the locking sleeve is in the home position. The projection is removable from the securing bracket by sliding the locking sleeve, against the spring. The securing bracket secures the locking sleeve in the axial direction and the locking sleeve securely the securing bracket in the radial direction. The two components can be removed, in which the user moves the locking sleeve against the spring. Dismantling is basically possible without tools.

One embodiment provides that the securing bow has a handle. The handle can be formed by two circumferentially converging flags. The flags are separated by a gap. The handle facilitates disassembly by a user can engage in the eye surrounded by the handle. The handle formed from two flags allows a handle for forces in the direction of tension stiff but with sufficient flexibility in the circumferential direction form. The safety bar can widen at a low tensile force to dissolve the rear handle.

BRIEF DESCRIPTION OF THE FIGURES

The following description explains the invention with reference to exemplary embodiments and figures. In the figures show:

Fig. 1 a hammer drill Fig. 2 shows a tool holder in longitudinal section in the plane II-II

Fig. 3 shows the tool holder in longitudinal section in the plane III-III Fig. 4 shows a base body of the tool holder in a longitudinal section of the plane II-II Fig. 5 a base body of the tool holder in a longitudinal section of the plane III-II Fig. 6 shows the tool holder in cross section in the Level IV-IV Fig. 7 shows the tool holder in cross-section in the plane VV

Fig. 8 shows the tool holder in a longitudinal section in the plane Vl-Vl offset to the axis Fig. 9 shows the tool holder in cross-section in the plane VII-VII Fig. 10 an alternative base body of the tool holder

Identical or functionally identical elements are indicated by the same reference numerals in the figures, unless stated otherwise. The relative position along the axis of individual elements is given below with front and back. Here, the working direction, typically equal to the line of sight of the user, is turned off during the use of the handheld power tool. Synonyms refer to the machine side at the front or the tool side at the rear. Unless otherwise indicated, the radial direction refers to the axis of the tool holder.

EMBODIMENTS OF THE INVENTION

Fig. 1 shows an example of a chiseling hand tool machine schematically a hammer drill 1. A user can perform the hammer drill 1 by means of a handle 2 and thereby take the hammer drill 1 by means of a system switch 3 in operation. The exemplary hammer drill 1 rotates a drill 4 or another tool continuously about a working axis 5 and thereby strikes the drill 4 in the direction of impact 6 along the working axis 5 in a background. Preferably, the rotational movement and the impact function can be activated individually by the user. An insertion end 7 of the drill bit 4 is releasably locked in a tool holder 8 of the power tool. The drill bit 4 can be removed in the direction of impact 6 from the tool holder 8. A primary drive of the hammer drill 1 is a motor 9, which drives a hammer mechanism 10 and an output shaft 11. The driven shaft 11 rotates the tool holder 8 about the axis 5. The hammer mechanism 10 is, for example, a pneumatic percussion 10. A pathogen 12 and a racket 13 are in the percussion 10 along the working axis 5, for example in a guide tube 14, movably guided. The exciter 12 is coupled via an eccentric 15 or a wobble finger to the motor 9 and forced to a periodic, linear movement. An air spring formed by a pneumatic chamber 16 between exciter 12 and racket 13 couples a movement of the racket 13 to the movement of the exciter 12 at. The racket 13 can strike directly on a striking surface of the drill bit 4 or indirectly transfer part of its pulse to the drill bit 4 via a substantially resting intermediate racket 16. The hammer mechanism 10 and preferably the further drive components are arranged within a machine housing 17.

FIG. 2 shows the tool holder 8 of the hammer drill 1 in a first longitudinal section along the axis 5 and FIG. 3 in a longitudinal section rotated by 90 °. Figures 6 to 8 show a plurality of perpendicular to the axis 5 extending cross-sections of the tool holder. 8

The tool holder 8 has a base body 18, via which the torque is transmitted from the motor 9 to the insertion end 7. The exemplary monolithic base body 18 consists of a tube 19 and a flange 20. The main body 18 is made for example of a steel tube. The tube 19 and the flange 20 are concentric with the working axis 5. A manually operable tool latch 21 is disposed on the tube 19 which locks an inserted into the tube 19 spigot 7. A preferably manually releasable flange lock 22 is arranged around the flange 20, which rotatably couples the flange 20 with the output shaft 11. The tube 19 has a substantially prismatic outer surface, which is preferably derived from a circular cylinder having an outer diameter 23. The outer surface may be withdrawn in a sector or in two diametrically opposite sectors to key surfaces 24 relative to the outer diameter 23. The key surfaces 24 are preferably flat. The other sectors 25 of the outer surface are preferably circular cylindrical. The tube 19 defined by its radially to the axis 5 facing inner surfaces wall surfaces of a receiving space 26 for receiving the insertion end 7. The inner diameter 27 of the receiving space 26 is approximately equal to the diameter of the common SDS-Einsteckendes 7 of hammer drills 4. The length 28 of the tube 19 is sufficient to be able to fully absorb the SDS insertion end 7 with its locking grooves and rotary driving grooves. A striking surface of the male end 7 projects slightly forward beyond the tube 19 to receive the impact of the intermediate beater 29 or beater 13. The tool lock 21 has at least one locking element 30. The locking elements 30 protrude partially into the receiving space 26 and can dodge for insertion and removal of the tool 4 from the receiving space 26 in the radial direction. The tool lock 21 has a sleeve 31 guided on the bushing 31. The bushing 31 is pushed in the locking position over the locking elements 30 such that their radial movement is inhibited and the locking elements 30 are forced into engagement with the receiving space 26. The user can move the bushing 31 by means of a grip sleeve 32 along the axis 5 in order to cancel the radial inhibition of the locking elements 30. Examples of the locking elements 30 are balls, cylinders, pivoted pawls.

The exemplary tool lock 21 has two locking balls 30 as locking elements. The locking balls 30 are each in a, preferably elongated to the axis 5 parallel, bearing shell 33. The bearing shell 33 is open in the radial direction to the receiving space 26 so that the locking balls 30 protrude into the receiving space 26. The bearing shell 33 is tapered towards the axis 5, so that the locking balls 30 can not fall into the receiving space 26. The locking balls 30 may be movable in the bearing shell 33 along the axis 5. The bearing shell 33 is preferably formed in the flat key surfaces 24. The locking balls 30 are preferably about half of their diameter beyond the key surface 24 addition.

An inhibition of the locking balls 30 in the radial direction takes place through a hollow cylindrical inner surface 34 of the bush 31. The bushing 31 overlaps along the axis 5 preferably only with a rear portion of the bearing shell 33. The locking balls 30 can in the front portion radially completely from the receiving space 26th dodge. A slider 35 holds the locking balls 30 in the rear portion, ie within the bushing 31. The slider 35 is on the pipe 19th along the axis 5, relative to the sleeve 31 slidably. A spring 36 pushes the slider 35 for a basic position against the bushing 31. A to the bush 31 facing thrust surface 37 of the slider 35 overlaps in the radial direction at least partially with the locking balls 30. If the locking balls 30 are in the front portion of the bearing shell 33, touches the thrust surface 37, the locking balls 30. The thrust surface 37 may have a concave curved, for example, Hohlkalotten-shaped contour. The slider 35 is preferably formed as a tube 19 spanning the ring. The slider 35 is guided on the key surfaces 24. When inserting the tool 4, the slider 35 is indirectly removed by the locking balls 30 against the spring force of the bush 31, the locking balls 30 can slide in the front portion of the bearing shell 33 and dodge in the radial direction of the insertion. Once the spigot 7 is fully inserted, the locking balls 30 fall into the locking grooves of the spigot end 7 and the spool 35, driven by the spring 36, pushes the locking balls 30 under the bushing 31.

The tool holder 8 has a rotational drive for the insertion end 7, which transmits the rotational movement of the tube 19 to the insertion end 7. The rotational drive is formed by one, two or more, preferably prismatic, rotational engagement webs 38. The rotary driving web 38 is aligned parallel to the axis 5. The rotary driving web 38 has its largest dimension along the axis 5 and the preferably trapezoidal cross section of the rotary driving web 38 is constant along the axis 5. The rotary driving bar 38 rises along a vertical direction 39 from the otherwise concave, preferably cylindrical inner surface 40 of the receiving space 26 to the axis 5. The vertical direction 39 is the cylindrical geometry of the tool holder 8 in accordance with cylindrical coordinates defined as follows: the vertical The vertical direction 39 is also perpendicular to the axis 5. The natural understanding of height and vertical direction 39 is obtained by rolling the inner surface 40. Based on a Cartesian coordinate system, each rotary driving web has 38th its own vertical direction 39. The rotary driving web 38 is limited in its determined in the circumferential direction 41 width by two driving surfaces 42. The preferably flat driving surface 42 transmits a torque from the tube 19 to the insertion 7. The driving surface 42 is in substantially parallel to a radial direction; the driving surface 42 lies in a plane with the axis 5. A roof surface 43 of the rotary driving web 38 closes the rotary driving web 38 in the radial direction and defines its height. The roof surface 43 faces the axis 5, in particular, the vertical direction 39 may be perpendicular to the roof surface 43.

The illustrated embodiment has an inserted into the tube 19 insert 44, which forms the bearing shells 33 for the locking elements 30 and the Drehitnahmestege 38 for the rotary driving.

The tube 19 has coaxial with the axis 5, a cylindrical cavity which is equal in size to the receiving space 26. The cylindrical shape may comprise circular cylindrical and prismatic with at least sixfold symmetry. The tube 19 is opened along a direction transverse to the axis 5 by a prismatic recess 45 (see Figures 4 and 5). The recess 45 may form one or two opposing openings 46 through the wall of the tube 19. The opening has an edge closed about the alignment axis 47. The recess 45 has a front surface 48 pointing in the removal direction 6 and a rear surface 49 facing the removal direction 6. Two lateral surfaces 50 of the recess 45 connect the front surface 48 to the rear surface 49. The surfaces 48, 49, 50 are parallel to an alignment axis 47. The alignment axis 47 defines the orientation of the recess 45 and the surfaces 50 delimiting it. By way of example, the alignment axis 47 may be determined based on the connecting line of the center (centroid) of the opening on the outside of the tube 19 and on the inside of the tube 19. The recess 45 may also be formed in the shape of a truncated pyramid. The surfaces 48, 49, 50 are inclined relative to each other such that a cross section enclosed by them monotonically decreases in a direction along the alignment axis 47. The recess 45 expands the cavity of the tube 19 with respect to the inner diameter 27 preferably in all directions within a plane perpendicular to the axis 5. In particular, a distance 51 of the lateral surfaces 50 is preferably greater than the inner diameter 27. The cylindrical inner surface of the tube 19 can be divided by the recess 45 in two completely separated from each other front cylindrical inner surface 52 and a rear cylindrical inner surface 53.

The outer contour of the insert 44 is formed complementary to the recess 45. The exemplary insert 44 has a substantially cuboidal outer contour, with a for example, front rounded end face. The along the alignment axis 47 and along the axis 5 extending side surfaces 54 are preferably flat against the complementary lateral surfaces of the recess 45. The side surfaces 54 may be parallel to at least one of the axis 5 and the alignment axis 47.

A width 55 and a height 56 of the insert 44 are greater than the diameter 27 of the receiving space 26. The height 56 is determined along the alignment axis 47 and the width 55 perpendicular to the alignment axis 47 in each case in a projection on a plane perpendicular to the axis 5 , A length 57 of the insert 44, ergo the recess 45, is less than the length 28 of the cylindrical tube 19. The insert 44 has a coaxial with the axis 5 extending cavity. The inner surface 58 of the insert 44 is substantially concave, preferably cylindrical. An inner diameter 59 of the insert 44 is equal to or slightly larger than the inner diameter 27 of the tube 19. The receiving space 26 for the tool is composed of two or three sections. A portion 60 forms the cavity of the insert 44. The front cylindrical inner surface 52 of the tube 19 may have a front portion 61 adjacent the insert 44 and the rear cylindrical inner surface 53 of the tube 19 may form a rear portion 62 adjacent the insert 44. The outer sections 61, 62 formed by the tube 19 preferably have a slightly smaller inner diameter 27, whereby bending forces acting on the tool transversely to the axis 5 are transmitted directly to the tube 19 and the base body 18 without loading the insert 44. The tube 19 may be formed of a correspondingly tough steel. The height 56, i. the dimension along the alignment axis 47, the insert 44 is approximately equal to the corresponding outer dimension 63 of the tube 19. The exposed outer surfaces 64 (top surfaces) of the insert 44 are largely flush with the base body 18 from, here by way of example with the flat key surfaces 24. The above described bearing shell 33 for the locking ball 30 is formed in one or both top surfaces 64. The top surfaces 64 of the insert 44 are preferably flat.

The insert 44 is formed with the rotary driving webs 38. Preferably, all Drehitnahmestege 38 of the tool holder 8 are part of the insert 44. Number, geometry and orientation of the rotary driving webs 38 is as described above. The rotary driving web 38 project from the concave inner surface 58 of the insert 44 in the vertical direction 39. The vertical direction 39 extends on the respective connecting line from the rotary driving web 38 to the axis 5. The vertical direction 39 of at least one or preferably all rotary driving webs 38 is inclined, for example perpendicular, to the alignment axis 47 of the recess 45. The rotary driving web 38 is supported on the tube 19 in its vertical direction 39. The vertical direction 39 of the rotary trip bar 38 extends through the side surface 54 of the insert 44 concealed by the tube 19 and not through the exposed top surface 64. When the insert 44 is inserted into the recess 45, the roof surface 43 of the rotary trip bar 38 is partially or entirely off the axis 5 preferably completely away from the axis 5.

The relative inclination of the two directions 39, 47 is determined in a projection on the plane perpendicular to the axis 5, if the alignment axis 47 should not be perpendicular to the axis 5.

The insert 44 with the rotary driving webs 38 is preferably monolithic. Monolithic is to be understood as the opposite of a body composed of two or more parts. The monolithic insert 44 has no joining zones, neither positive, non-positive nor material-locking, e.g. by soldering, gluing, welding, art. The insert 44 is formed from a blank.

The insert 44 is preferably located loosely in the recess 45 so as to be removable from the base body 18 if required without assembly tools. In particular, the insert 44 is not in a material-locking manner, e.g. glued, soldered, welded, fastened in the tube 19. Once a hammer drill 4 is inserted into the receiving space 26 and thus pushed through the cylindrical cavity of the insert 44, the insert 44 is stabilized. The slider 35 may further be configured to hold the insert 44 in position. The slider encloses annularly the tube 19 of the base body 18 and has an inner contour 65 which rests against the top surfaces 64 of the insert 44. In the locking basic position of the tool holder 8, the slider 35 is arranged approximately centrally to the insert 44. The length 57 of the insert 44 is further designed so that when inserting the hammer drill 4, the slider 35 is not pushed down from the insert 44.

The recess 45 may be closed along the alignment axis 47 on one side by a bottom, ie be cup-shaped. A thickness of the bottom is equal to or less than the wall thickness of the tube 19. The associated insert 44 surrounds annularly the receiving space 26. The insert 44 has only one exposed top surface 64 and a Bearing 33. Further, the insert 44 has within its cavity one or more rotational engagement webs 38 for the rotary driving.

The assemblies of the flange lock 22 and the tool lock 21 can be removed from the main body 18. This is particularly useful for replacing the two actuating sleeves 66, 32, the locking balls 30 and possibly the insert 44.

The actuating sleeve 32 is supported on an axially immovable securing bracket 68 by means of an end face 67 pointing in the withdrawal direction 6. The securing bracket 68 is seated in a groove 69, which is provided along the circumference at a tool-side end of the main body 18. The exemplary actuating sleeve 32 has an annular or hollow cylindrical projection 70 which encloses the securing bracket 68 in the radial direction. A radial clearance between the circlip 68 and the projection 70 is less than a depth of the groove 69, whereby the circlip 68 is caught in the groove 69. By way of example, the projection 70 with its radial inner surface 71 can lie directly against the securing bow 68. The user can axially displace the actuating sleeve 32 against a spring 36 to release the securing bracket 68 in the radial direction and to remove the securing bracket 68 from the groove 69.

The safety bracket 68 is constructed substantially symmetrical. A web 72 connects two opposite clamping legs 73. The two clamping legs 73 engage in the groove 69 of the base body 18 a. The web 72 may also engage or be exposed in the groove 69. The tube 19 is only partially enclosed by the securing bracket 68 in order to be able to remove it without great effort. The clamping legs 73 are to be spread slightly to avoid accidental falling out. The enclosed angle 74 is less than 250 degrees and is preferably in the range between 210 degrees and 240 degrees. The angle 74 is measured on the groove bottom 75 between the two along the circumferential direction 41 outermost of the clamping legs 73 touched points 76. The inner contour of the securing bracket 68 between the two points 76 is preferably largely circular-segment-shaped, and lies continuously against the groove bottom 75. The forwardly facing in the insertion direction portions 77 of the clamping legs 73 define an opening 78 of the securing bracket 68. The front portions 77 are pushed over in the insertion direction over the groove bottom 75 and therefore exposed. The opening width 78, ie the distance 78 of the clamping legs 73, is in the range of at least 80%, preferably between 87% and 97%, of the diameter 79 of the groove 69. The safety bracket 68 has a handle. The handle is arranged on the side opposite the base body 18 of the web 72. The exemplary handle 80 consists of two lugs 80, each beginning at one end of the web 72 and spaced in the radial direction of the web 72 in the circumferential direction 41 converge. The tips of the two lugs 80 may be separated by a gap 81. The user may, for example, with a screwdriver or other flat tool in the 72 surrounded by the web 72 and handle 80 slot 82 to lift the safety bracket 68 from the groove 69.

The securing bracket 68 is preferably plate-shaped. The clamping legs 73 have a width, measured in the radial direction 39, which is significantly greater than the thickness, measured along the axis 5, of the securing bracket 68. A width of the web 72 is less than the width of the clamping legs 73rd

The securing bracket 68 may have a pin 83 projecting from the web 72 in the radial direction to the axis 5. The main body 18 has a corresponding recess 84 to receive the mandrel 83. The recess 84 is, at least in the circumferential direction, approximately positively to the mandrel 83. The safety bracket 68 is prevented from rotating about the working axis 5 and thus has a fixed azimuth, i. a fixed angular orientation. The handle 80 and the locking balls 30 have e.g. the same azimuth and lie in an alignment parallel to the working axis 5. An outer contour of the base body 18 is provided with the flattened key surface 24 in the region of the locking balls 30. The flattened key surface 24 is preferably extended up to the annular groove 69. In front of the slot 82 is thereby a cavity 60 between the bushing 31 and the key surface 24, in which the user can insert the puller.

The circlip 68 finds particular attention in the illustrated embodiment with the removable insert 44. Further, there is an interest in the securing bracket 68 in a one-piece receiving space 85, the entire wall surface 86 is formed by a tube 87 of the base body 88.

A cover 89 made of a soft plastic is attached to the tip of the base body 18 and protects the two latches 21, 22 from dust. The cover 89 can be pulled off the base body 18 by hand. The exemplary flange 20 can be pushed onto the output shaft 11. The releasable flange lock 22 allows the flange 20 to apply torsionally rigidly to the output shaft 11 and to release it without tools. The flange lock 22 has a plurality of coupling balls 90 or coupling pins which engage through radial openings 46 of the flange 20 in corresponding recesses of the output shaft 11. An actuating sleeve 66 of the flange lock 22 is placed on the flange 20 and movable along the working axis 5. A spring 36 holds the actuating sleeve 66 in a locking position in which a radial movement of the coupling balls 90 is inhibited and thus they are forced into engagement with the output shaft 11. The user can move the actuating sleeve 66, preferably in withdrawal direction 6 of the tool 4 against the spring 36 until the coupling balls 90 can radially escape and disengage. The tool holder 8 can be removed.

Although the removable tool holder 8 is a preferred embodiment for many applications, a permanent attachment or tool-only attachment of the body 18 to the output shaft 11 is advantageous for other applications, e.g. for a simple and compact construction. The main body 18 may for example be formed integrally with a guide tube of the intermediate racket 16 or the racket 13.

Claims

1. tool holder (8) for a hand tool with:

a tube (19; 87) whose inner surface (52, 53; 86) defines a receiving space (26; 85) coaxial with a working axis (5) for an insertion end (7) of a tool (4) and in its outer surface (24; 25) is formed around the axis (5) encircling groove (69),

a radially movable locking member (30) partially projecting into the receiving space (26; 85) through a radial opening in the tube (19; 87),

a locking sleeve (31, 32) which is movably guided on the outer surface (24, 25) of the tube (19, 87) along the axis (5), which in a basic position bears against the locking element (30) in the radial direction,

a spring (36) which drives the locking sleeve (31, 32) into the basic position, a securing bow (68) on which the locking sleeve (31, 32) is supported against the force of the spring (36), the securing bow (68 ) is inserted into the groove (69) and the groove (69) encloses less than 250 degrees.

2. Tool holder (8) according to claim 1, characterized in that the outer surface (24, 25) has a to the groove (69) along the axis (5) adjacent planar key surface (24) and the securing bracket (68) has a rotation ( 83, 84) for a to the key surface (24) defined orientation of the securing bracket (68).

3. tool holder (8) according to claim 2, characterized in that the securing bracket (68) has two opposite clamping legs (73) which rest in the groove (69), and between the clamping legs (73) to the axis (5) above Mandrel (83), wherein the mandrel (83) engages in a circumferential direction (41) limited recess (84).

4. Tool holder (8) according to any one of the preceding claims, characterized in that the locking sleeve (31, 32) in a direction (6) to the

Circlip (68) projecting hollow cylindrical projection (70) whose radial inner surface (71) on the securing bracket (68) abuts when the locking sleeve (31, 32) in the normal position, and the projection (70) of the securing bracket (68 ) is removable by moving the locking sleeve (31, 32) against the spring (36).

5. Tool holder (8) according to any one of the preceding claims, characterized in that the securing bracket (68) has a handle (80).

Tool holder (8) according to claim 5, characterized in that the handle (80) by two in the circumferential direction (41) converging flags (80) is formed.

Tool holder (8) according to claim 6, characterized in that the lugs (80) are separated from each other by a gap (81).

Tool holder (8) according to one of the preceding claims, characterized in that the securing bracket (68) surrounds the groove (69) between 200 degrees and 240 degrees.